What you should know about wood pellet raw material?

The requirement of the raw material of wood wood pellet machine directly affects the quality of wood pellets, high quality pellets requires good controlling of raw material.

What are these requirements of raw material when pelletizing pellets?

Size of raw material

The size of raw material is required when processing wood pellet. Normally, the size of raw material is no more than 5mm. The specific size of material after crushing depends on the except size of pellets and the aperture of pellet die hole. Too large or too small will also influence the yield and quality, or cause the problem of blocking of machine.

Moisture content of raw material

During the process of making wood pellets. There are also strict requirements of moisture content of raw material. No matter what kind of raw material is, the moisture content must be controlled within 10-15%. Moisture content too large or too small will cause pellets easy to  break or loose.

Adhesive free

There is no need to add any adhesive when making wood pellet, because the wood itself is a crude fiber raw material with certain adhesiveness. It can be formed naturally by the extrusion of the wood pellet machine. Though the adhesive is not needed, the moisture content is non negligible.

Different raw materials can be doped

The wood pellet machine can not only deal with a kind of wood chips, but also other varieties of wood chips. To a wide range, raw materials mixed with crop straw, fruit shell, peanut shell, rice straw and so on can also be used to produce pellets. The pellets made of other kinds of wood chips are still high quality pellets. When the straw is added, the pellet quality will be slightly lower due to the attribute of the sawdust itself. At this time, it can not be called wood pellet but straw pellets.

Don’t worry about mouldy material

Sometimes, when raw materials are collected for a long time because of over collection or other reasons, the raw materials will be mildew and black after a period of time. At this time, pressed pellets can not reach the required density and heat, so it is a great pity to throw them away. Do not worry about the mildewy raw materials. As long as we add more than 50% fresh raw materials, they can still be processed into pellets, the more the new raw materials will be added, the higher the quality of the pellets will be. The amount of raw materials are added according to individual circumstances.

The above five points basically contain all the information about the raw material of the wood pellet. In either case, we can produce high quality pellet fuel following the requirements.

Different types of raw material

Generally, hardwood has high density, such as birch, beech wood, poplar, yew, hard maple, elm and so on, hard wood usually contains less water compared to soft wood and can burn longer time.
Soft wood is usually gymnosperm, such as pine, mahogany, cedar, fir, spruce and so on. The combustion of soft wood pellets is more sufficient than the hardwood.
Arguably, both raw materials have their own advantages.
In the actual production process, the water content of the raw material should be controlled at about 10-15% before the pellets are pressed. And during the granulation process, heat and pressure also changed the structure and density of raw materials, so the combustion values of hardwood and soft wood pellets  with the same weight are equal.
Although some people think that hardwood pellets are more environmentally friendly than soft wood pellets, they left less ash after burning. The fact is that the ash content depends on the cleanliness of the wood pellets rather than the cleanliness of the raw materials. According to the statistics, some hardwood, on the contrary, contains more ash. In addition, the cleanliness of the raw material and the quality of the wood pellet machine also affect the ash content. In contrast, the quality of wood pellet machine can really decide the quality of wood pellet. If the qualified raw material is used, the qualified wood pellet can also be manufactured if the qualified wood pellet machine is used.

Relative reading: What are raw materials of wood pellet machine?